Characterization of the neutral extractable hydroxyproline containing peptides (NEHYP), obtained from normal rat liver by heterogeneity, content of hydroxylysine, galactosyl hydroxylysine and glucosylgalactosyl hydroxylysine, as well as ratio of 3-hydroxyproline to 4 hydroxyproline. Comparison of the data generated above with those obtained from NEHYP extracted from the livers of rats exposed to ethanol. Characterization of a pepsin digestible inhibitor of lysosomal collagenase found in a netralized PCA extract of normal rat liver and with increased inhibitory activity in a PCA extract of the livers from rats which had received ethanol. Development of an assay to study the effect of the inhibitor on the incorporation of C-14 labelled proline into collagen hydroxyproline in rat liver slices. Study of the distribution of lysosomal collagenase in hepatocytes, Kupfer cells and other cellular elements of rat liver.